JP2003264205A - Manufacturing method of semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that a semiconductor chip cannot be firmly adhered to a base due to insufficient wetting of an adhesive caused by the warp of the base on which the semiconductor chips are mounted to deteriorate reliability in a conventional manufacturing method of a semiconductor device. <P>SOLUTION: The base having the warp is corrected to a proper shape by curing the adhesive and a sealing resin at the same time under pressure for compressing and curing the sealing resin. The insufficient wetting of the adhesive is dissolved to firmly fix the semiconductor chip on the base. Thereby the semiconductor device having excellent reliability can be achieved by a simple process. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a semiconductor device.

[0002]

2. Description of the Related Art In recent years, semiconductor devices have been made smaller and have higher performance in order to realize electronic devices of small size, light weight and high performance.
GA (Ball, Grid, Array) and LGA (L
and Grid, Array),
The number of semiconductor devices of a type in which external connection terminals are arranged in a grid pattern is increasing. In addition, a type in which a plurality of semiconductor chips of the same type or different types are two-dimensionally arranged inside the semiconductor device or three-dimensionally stacked and mounted is also increasing.

An example of a conventional semiconductor device is shown below in FIG.
A description will be given with reference to FIGS. Figure 7
8A to 8B are cross-sectional views showing a typical internal structure of a conventional BGA type semiconductor device.

The semiconductor device shown in FIG. 7A has a printed wiring board 102, a semiconductor chip 101 adhered and fixed on the printed wiring board 102, and a printed wiring board 102.
Adhesive 104 for bonding the semiconductor chip 101 to the semiconductor chip 101
A wire 103 for electrically connecting the semiconductor chip 101 and the printed wiring board 102, the semiconductor chip 101,
A sealing resin 105 for sealing the wire 103 and the adhesive 104 with resin, and a metal ball 106.

The printed wiring board 102 has an insulating member 102e, a plurality of wiring patterns 102b located on the insulating member 102e, and internal connection lands 102a.
And a plurality of external terminal lands 102d located below the insulating member 102e and the insulating member 102e, and the wiring pattern 102b and the internal connecting lands 10d.
2a and via hole 102c for electrically connecting external terminal land 102d. The printed wiring board 102 may be referred to as a substrate or an interposer.

In FIG. 7B, in addition to the structure shown in FIG. 7A, a second semiconductor chip 111 is bonded and fixed on the semiconductor chip 101 by a second adhesive 114. Semiconductor chip 111 and printed wiring board 10
2 is electrically connected to the second wire 113.

FIG. 7C shows a structure in which two semiconductor chips are arranged in a plane.

In FIG. 8A, the semiconductor chip 101 in FIG. 7B is printed wiring board 1 via bumps 108.
No. 02 and flip-chip connected structure.

FIG. 8B shows a structure in which the second semiconductor chip 111 in FIG. 7B is flip-chip connected to the semiconductor chip 101 via bumps 118.

Among the structures shown in FIGS. 7A to 8B, the structure shown in FIG. 7A is disclosed in Japanese Patent Laid-Open No. 9-1210.
In the No. 02 publication, the structures shown in FIGS. 7B and 8A are
It is disclosed in JP-A-11-204720.

Next, a process of assembling the semiconductor device shown in FIG. 7A will be described with reference to FIGS. 9A to 10C. 9A to 10C are cross-sectional views showing the steps of manufacturing the semiconductor device shown in FIG. 7A. 9A to 9C are die-bonding steps, and FIG.
Is called a die bond curing step, FIG. 10A is called a wire bonding step, FIG. 10B is called a sealing step, and FIG. 10C is called an after cure step.

First, in any step (die bonding step) of FIGS. 9A to 9C, the adhesive 104 is used to connect the printed wiring board 102 and the semiconductor chip 101. Here, one of the steps in FIGS. 9A to 9C is selected depending on the type of the adhesive 104 used. In FIG. 9A, after applying a paste type adhesive agent 104 on the printed wiring board 102 at room temperature, the semiconductor chip 101 is mounted. In FIG. 9B, the semiconductor chip 101 is mounted after the film type adhesive 104 is thermocompression bonded onto the printed wiring board 102. In FIG. 9C, the semiconductor chip 101 to which the film type adhesive material 104 has been attached in advance.
After being mounted on the printed wiring board 102, thermocompression bonding is performed.

Next, in a step (die bond cure step) shown in FIG. 9D, the printed wiring board 102 on which the semiconductor chip 101 is mounted is placed in an oven 109 and heated to heat cure the adhesive 104. Then, the semiconductor chip 101 is completely bonded and fixed onto the printed wiring board 102.

Next, in the step (wire bonding step) shown in FIG. 10A, the semiconductor chip 1 is connected by the wire 103.
01 and the internal connection land 102a in the printed wiring board 102 are connected.

Next, in the step (sealing step) shown in FIG. 10B, the semiconductor device assembled in the above steps is held in the space between the upper die 120a and the lower die 120b, Semiconductor chip 101 and printed wiring board 102
Then, the sealing resin 105 is formed so as to protect and cover the wire 103 and the adhesive 104.

Next, in a step (after-cure step) shown in FIG. 10C, the sealed semiconductor device is put into the oven 109 to completely cure the sealing resin 105. Mounting of the metal balls 106 shown in FIG.
Although it is after the step shown in (c), illustration is omitted.

Next, a process of assembling the semiconductor device of FIG. 7B will be described with reference to FIGS. 11A to 14B. 11 (a) to 14 (b) are shown in FIG. 7 (b).
FIG. 6 is a cross-sectional view showing a step of manufacturing the semiconductor device shown in FIG. 11A to 11C are the first die bond step, FIG. 11D is the first die bond cure step, and FIG.
2 (a) to 2 (c) in the second die bonding step, FIG.
14A is a second die bond curing step, FIG. 13B is a wire bonding step, FIG. 14A is a sealing step, and FIG.
(B) is called an after-cure process.

First, in the steps shown in FIGS. 11A to 11D, steps similar to those in FIGS. 9A to 9D are performed.

Next, in a step shown in FIGS. 12A to 12C, the second semiconductor chip 11 is formed on the semiconductor chip 101.
1 is bonded by the second adhesive 114. Figure 12 (a)
9 (a)-
There are three methods similar to those shown in (c).

Next, in the step shown in FIG. 13A, the second adhesive 114 is thermoset in the oven 109 to completely bond and fix the second semiconductor chip 111 and the semiconductor chip 101.

Next, in the steps shown in FIGS. 13B to 14B, the same steps as those in FIGS. 10A to 10C are performed.

[0022]

However, in the conventional manufacturing method, insufficient wetting occurs at the adhesive interface of the adhesive. The insufficient wetting causes a decrease in reliability of the semiconductor device. Hereinafter, the cause of insufficient wetting will be described with reference to FIGS. 15 (a) to 16 (b). In addition, FIG. 15 (a), (b), FIG. 16 (a), (b),
FIG. 11 is a cross-sectional view for explaining a defect in the conventional method for manufacturing a semiconductor device.

There are two causes of insufficient wetting. One is the warp of the base that adheres the semiconductor chip with an adhesive, and the other is a void generated inside the adhesive.

FIG. 15A shows a semiconductor device in the die bond cure process. Here, the semiconductor chip 101 is mounted on the warped printed wiring board 102. There are two causes of the warp of the printed wiring 102.
One is the warp that occurs when the printed wiring board 102 is manufactured, and the other is the warp that occurs during die bond cure (FIG. 15A).

The first cause of the warp will be described. Figure 1
The printed wiring board 102 shown in FIG.
2e is an internal connection land 102a and a wiring pattern 1
The layer 02b and the layer for external terminal land 102d sandwich the layer, and the wiring pattern 102b and the external terminal land 102d are connected by a via hole 102c. Here, the printed wiring board (double-sided printed wiring board) 102, which is a laminate of three layers, is
The initial stress of the insulating member 102e, the stress due to the difference in the area of the conductor layer between the upper surface and the lower surface of the insulating member 102e,
Processing distortion and the like occur in the outer shape processing step and the step of forming the via hole 102c. Due to such factors,
The printed wiring board 102 initially has a warp.

Next, the second cause of the warp will be described. When the semiconductor device is heated in the oven 109 in the die bond curing step shown in FIG.
4, the semiconductor chip 101 and the printed wiring board 102,
The stress due to each thermal expansion and the stress due to the thermosetting shrinkage of the adhesive 104 work. The stress distribution at this time depends on the physical properties and size of each member, the temperature inside the oven 109, and the like.

Next, when the semiconductor device is taken out of the oven 109 and kept at room temperature, the semiconductor device has a curved shape due to the difference in thermal expansion coefficient between the printed wiring board 102 and the semiconductor chip 101. In general, the insulating member 102e of the printed wiring board 102 is made of an organic material, and the semiconductor chip 101 is made of an inorganic material having a thermal expansion coefficient smaller than that of the organic material, so that the entire shape is often convex. However, it may be concave depending on the physical properties and size of each member.

Next, the voids inside the adhesive, which is the second cause of insufficient wetting of the adhesive interface, will be described.

First, when the adhesive 104 is a paste type, the causes of voids are as follows: insufficient agitation before adhesion, air entrapment during application, and a gap between the wiring pattern 102b and the insulating member 102e during adhesion. Examples include defective filling of steps and entrainment of outgas during thermosetting.

When the adhesive 104 is of a film type, the step of filling the step between the wiring pattern 102b and the insulating member 102e is poorer than that of the paste type, and voids are likely to occur. In addition, voids may be mixed in the film type adhesive from the beginning. That is, the process of producing a film type adhesive is completed by dissolving a base adhesive resin in a solvent together with a filler and the like as a varnish, applying the varnish to a carrier film and then drying. However, at the time of drying, voids may be caused by the traces of volatilization of outgas, an area where the carrier film is insufficiently wet with varnish, and the like. In addition, voids are generated due to outgas even during heat curing.

Next, in the structure shown in FIG. 15B, a semiconductor chip 101 having a back surface to which a film-type adhesive agent 104 is attached is mounted on a warped printed wiring board 102. In this case, the printed wiring board 10
Since only the outer edge of the semiconductor chip 101 is bonded to the second chip 2 and the central part of the chip is not bonded, the central part of the chip becomes an insufficient wetting region.

In the structure shown in FIG. 16A, two semiconductor chips are stacked on the printed wiring board 102,
A paste type is used for the second adhesive 114. In this case, the semiconductor chip 101 and the printed wiring board 102 are not bonded to each other in the first die bonding process.
The convex warp of the upper surface of 01 is generated. Therefore, the second
When the semiconductor mounting chip 111 is die-bonded to the upper surface of the semiconductor chip 101, the second adhesive 1 is formed in the same manner as in FIG.
14 becomes insufficiently wet.

In the structure shown in FIG. 16B, two semiconductor chips are laminated on the printed wiring board 102, and the second adhesive 114 is a film type. Also in this case, as in FIG. 16A, the convex warpage occurs on the upper surface of the semiconductor chip 101. When the adhesive strength of the second adhesive 114 is low, the second semiconductor chip 11
When 1 is die-bonded to the upper surface of the semiconductor chip 101, only a part of the second semiconductor chip 111 is bonded to the base, so that a large area of insufficient wetting occurs.

As described above, in the conventional semiconductor device manufacturing method, when the die bond cure is completed,
Warpage of the base of the semiconductor chip and voids of the adhesive cause insufficient wetting of the interface of the adhesive. This reduces the adhesion between the semiconductor chip and the underlying structure. When a space is created inside the semiconductor device, the amount of moisture absorbed by the semiconductor device increases, and defects such as semiconductor chip damage, sealing resin damage, and metal wire damage are likely to occur due to vaporization and expansion of water due to reflow heating. Even before damage, defects such as corrosion of metal parts, current leakage due to impurity extraction, short circuit, and contamination are likely to occur due to increase in moisture absorption.

In particular, semiconductor chips in recent years are becoming larger due to the demand for higher performance. with this,
Since the area that must be adhered is increased, the influence of the warp of the printed wiring board becomes large, and the wettability of the adhesive agent is likely to decrease, so there is an increasing demand for suppression of insufficient wetting.

Further, an increase in the size of the semiconductor chip leads to an increase in the number of terminals and an increase in the required number of wirings. However, since the semiconductor device itself is required to be small in size, it replaces the conventional double-sided printed wiring board and has a multilayer structure. The number of printed wiring boards and built-up printed wiring boards is increasing.

In order to produce a multilayer printed wiring board, a step of laminating and molding a plurality of double-sided printed wiring boards at high temperature and high pressure and forming via holes for connecting the laminated printed wiring boards to each other. A process is required, and heat history and processing history are complicated. Therefore, the warp of the multilayer printed wiring board is worse than that of the double-sided printed wiring board. Further, in the build-up printed wiring board, the conductor pattern is laminated on the surface of the multilayer printed wiring board, and the problem of deterioration of the warp of the printed wiring board has become more important.

Due to the demand for higher performance and higher density packaging of semiconductor devices, there is a demand for semiconductor devices in which a plurality of semiconductor chips are stacked as shown in FIGS. 7 (b), 8 (a) and 8 (b). However, there is a problem in that the number of steps required to manufacture such a semiconductor device increases and the productivity decreases.

An object of the present invention is to provide a method of manufacturing a semiconductor device which is more reliable than conventional ones by taking a method of hardening an adhesive. At the same time, another object is to provide a method for manufacturing a semiconductor device with high productivity by simplifying the manufacturing method.

[0040]

According to a first method of manufacturing a semiconductor device of the present invention, a supporting body on which the semiconductor chip is mounted and an adhesive for adhering the semiconductor chip to the supporting body are sealed. A method of manufacturing a semiconductor device sealed with a resin, comprising the step of sealing the support, the semiconductor chip, and the adhesive with the sealing resin in a sealing mold, wherein the sealing resin Includes a step (a) of applying pressure to perform at least a part of the curing of the adhesive and at least a part of the sealing resin.

As a result, the resin sealing pressure acts as a hydrostatic pressure for pressing the semiconductor chip and the support,
The warp of the support can be corrected, and the generation of voids inside the adhesive can be suppressed. Therefore, the adhesion between the support and the semiconductor chip can be improved. Further, since the adhesive is cured at the same time as the sealing resin is cured, it is possible to simplify the process.

The semiconductor chip may be mounted on the support in a face-down manner, and the semiconductor chip may be electrically connected to the support by bumps.

A second semiconductor chip is mounted on the semiconductor chip with a second adhesive interposed therebetween, and in the step (a),
You may also perform at least one copy of the hardening of the said 2nd adhesive agent.

Thus, in the step (a), the second adhesive and the sealing resin are hardened so that the resin sealing pressure acts as a hydrostatic pressure for pressing the semiconductor chip, the second semiconductor chip and the support. Therefore, the warp of the support can be corrected, and the generation of voids inside the second adhesive can be suppressed. Therefore, the adhesion between the semiconductor chip and the second semiconductor chip can be improved. It is also possible to simplify the process.

The second semiconductor chip may be mounted on the semiconductor chip in a face-down manner, and the bumps may be used to electrically connect the second semiconductor chip and the semiconductor chip.

A plurality of the semiconductor chips may be arranged in a plane.

In the step (a), after the curing of the adhesive and the sealing resin is completed, the after-curing step required thereafter can be omitted, so that the step can be simplified. .

A second semiconductor device manufacturing method of the present invention is
A semiconductor device in which a semiconductor chip, a second semiconductor chip mounted on the semiconductor chip, and a second adhesive for bonding the semiconductor chip and the second semiconductor chip are sealed with a sealing resin. In the step of sealing the semiconductor chip, the second semiconductor chip, and the second adhesive with the sealing resin in a sealing mold, a pressure is applied to the sealing resin. Then, there is provided a step (a) of performing at least a part of the curing of the second adhesive and at least a part of the curing of the sealing resin.

As a result, even when the curing of the adhesive is completed at the time of starting the step (a), the second adhesive and the sealing resin are cured in the step (a). By doing so, the resin sealing pressure acts as a hydrostatic pressure that presses the semiconductor chip, the second semiconductor chip and the support, so that the warp of the support can be corrected, and the voids inside the second adhesive can be corrected. Occurrence can be suppressed. Therefore, the adhesion between the semiconductor chip and the second semiconductor chip can be improved.

The second semiconductor chip may be mounted on the semiconductor chip in a face-down manner, and the bumps may be used to electrically connect the second semiconductor chip and the semiconductor chip.

In the step (a), after the curing of the second adhesive and the sealing resin is completed, the after-curing step required thereafter can be omitted, so that the step can be simplified. Become.

[0052]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) First, regarding the structure of a semiconductor device to which the manufacturing method of this embodiment is applied,
This will be described with reference to FIG.

As shown in FIG. 2C, the semiconductor device according to the present embodiment has a printed wiring board 2, a semiconductor chip 1 bonded and fixed onto the printed wiring board 2, the printed wiring board 2 and the semiconductor chip. It is composed of an adhesive 4 for bonding 1 to each other, a wire 3 and a sealing resin 5.

The printed wiring board 2 has the insulating member 2
e, a plurality of wiring patterns 2b and internal connection lands 2a located above the insulating member 2e, a plurality of external terminal lands 2d located below the insulating member 2e, and an insulating member 2
The via hole 2c is formed so as to penetrate through e and electrically connects the wiring pattern 2b, the internal connection land 2a, and the external terminal land 2d.

The wire 3 electrically connects the printed wiring board 2 and the semiconductor chip 1. Land for external terminal 2
A metal ball (not shown) is mounted on d, and this is connected to an external printed wiring board (not shown) on which the semiconductor device is mounted. The sealing resin 5 is formed by covering the semiconductor chip 1, the wire 3 and the adhesive 4 formed on the printed wiring board 2 in order to protect them from the external environment.

Next, a method of manufacturing the semiconductor device of this embodiment will be described with reference to FIGS. 1 (a) to 1 (c) and 2 (a) to 2 (c). 1 (a) to (c) and FIG.
(A)-(c) is sectional drawing which shows the manufacturing process of the semiconductor device in 1st Embodiment.

First, in any step (die bonding step) of FIGS. 1A to 1C, the printed wiring board 2 and the semiconductor chip 1 are bonded to each other using the adhesive 4. Here, depending on the type of the adhesive 4 used, FIG.
Either step of (c) is selected.

In the step shown in FIG. 1A, the paste type adhesive 4 is applied on the printed wiring board 2 at room temperature.
After applying, the semiconductor chip 1 is mounted. Then 1
The adhesive 4 is temporarily cured by performing in-line curing for several tens of seconds to several minutes at 00 to 250 ° C., and the printed wiring board 2 and the semiconductor chip 1 are temporarily fixed and bonded. Here, the temporary curing of the adhesive 4 is a state in which the curing reaction is stopped at the initial stage, and the temporary fixing adhesion is a state in which the adhesive 4 is adhered by being temporarily cured.

In the step shown in FIG. 1B, the film type adhesive 4 is applied to the printed wiring board 2 in an amount of 50 to 50%.
Hold at 150 ° C. for several seconds and perform thermocompression bonding. Then, the semiconductor chip 1 is mounted and held at 100 to 200 [deg.] C. for several seconds to temporarily cure the adhesive 4 and temporarily bond the printed wiring board 2 and the semiconductor chip 1 together.

In the step shown in FIG. 1C, after mounting the semiconductor chip 1 to which the film type adhesive material 4 is attached in advance on the printed wiring board 2, 100
The printed wiring board 2 and the semiconductor chip 1 are temporarily fixed to each other by holding at a temperature of up to 200 ° C. for several seconds.

Here, the technical significance of each of the above die-bonding methods will be described.

The paste type adhesive used in FIG. 1 (a) has an advantage that the cost is significantly lower than that of the film type adhesive.

Unlike the paste type adhesive, the film type adhesive used in FIGS. 1 (b) and 1 (c) is stored at a low temperature, returned to room temperature when used, and stirred to adjust the viscosity. Work is unnecessary. further,
Since it is not necessary to apply it to the adhesive surface, voids due to air entrapment can be eliminated.

Further, when a film type adhesive is used, it is easy to control the area of the wet extension of the adhesive extending outside the semiconductor chip after die bonding. Particularly, in the method of attaching the adhesive to the back surface of the semiconductor chip in advance (FIG. 1C), since the semiconductor chip on the wafer is cut out after the adhesive is attached to the wafer, the size of the adhesive is the size of the semiconductor chip. Is almost the same, and almost no wetting and spreading occurs.

As described above, although there are various die bonding methods, which type of adhesive is selected and which bonding method is selected depend on the required quality and cost. An epoxy resin can be used as the material of the adhesive 4.

Next, in a step (wire bonding step) shown in FIG. 2A, the semiconductor chip 1 and the internal connection land 2a in the printed wiring board 2 are connected by the wire 3. Here, as a method of joining the wires 3, a method of heating an adherend and jointly using pressure and ultrasonic vibration is generally used.

Next, the step shown in FIG. 2B (sealing step)
Then, the semiconductor device assembled so far is held between the upper mold 20a and the lower mold 20b heated to 160 to 190 ° C., and the sealing resin 5 is transfer-injected. After the completion of the injection, the sealing resin 5 is cured to a predetermined degree by performing a heat treatment by holding at 160 to 190 ° C. for 30 seconds to 2 minutes. This curing is performed to such an extent that the sealing resin 5 is not sufficiently cured when the semiconductor device that has been sealed is taken out from the mold, so that the sealing resin 5 is not damaged. At this time, the adhesive 4 that was in the temporarily cured state is also cured to a predetermined degree.

At the time of this heat treatment, 50 kgf / cm ² to 2 kg is used to crush the air mixed in at the time of injecting the resin.
A pressure of about 50 kgf / cm ² is applied to the sealing resin 5.
This pressure also acts as a hydrostatic pressure that presses the semiconductor chip 1 and the printed wiring board 2 against the lower mold 20b, so that the warpage of the semiconductor chip 1 and the printed wiring board 2 is corrected to a flat state, and at the same time, the adhesive 4 Voids occurring in the interface underwetting region and inside the adhesive 4 are crushed. Since the sealing resin 5 and the adhesive 4 are cured in this state, it is possible to obtain a uniform and strong adhesive interface without an insufficient wetting region.

Next, in the step (after-cure step) shown in FIG.
The sealing resin 5 and the adhesive 4 are completely cured by holding them at 0 to 190 ° C. for 3 to 8 hours for heat treatment. For complete curing of the adhesive 4, generally 150 to 180 ° C
It is preferable to perform heat treatment for 30 minutes to 1 hour at
The adhesive 4 is also completely cured in the after-curing process. Through the above steps, the manufacturing of the semiconductor device in this embodiment is completed. Here, the step of attaching the metal balls is omitted.

In order to confirm the effect obtained by this embodiment, the semiconductor device after resin sealing was cross-section polished and the state of the adhesive 4 was observed. As a result, a number of insufficient wetting regions and voids were generated in the conventional manufacturing method including the die bond curing step, but they disappeared in the manufacturing method according to the present embodiment, and a uniform adhesive interface was formed as compared with the conventional method. I found out.

That is, according to the manufacturing method of the present embodiment,
Since the adhesive strength between the semiconductor chip 1 and the printed wiring board 2 can be increased as compared with the case of the conventional manufacturing method, the reliability of the semiconductor device can be improved.

Further, it is possible to omit the die bond curing step, which is necessary in the conventional manufacturing method, simplify the manufacturing process, and improve the productivity.

The adhesive 4 and the sealing resin 5 are the same as those shown in FIG.
It may be completely cured in the step shown in (c), or at least one of the adhesive 4 and the sealing resin 5 is
It may be completely cured in the step shown in FIG. That is, when the step of FIG. 2B is started, the adhesive 4 is in a temporarily cured state, and when the step of FIG.
If the adhesive 4 is almost cured without the insufficient wetting area, the adhesiveness can be improved.

Although omitted in the steps shown in FIGS. 1A to 2C, it is possible to improve the wire bondability in the wire bonding step and the adhesion with the sealing resin. For the purpose, it is possible to insert the plasma cleaning step after die bonding or wire bonding, since it does not directly affect the thermal curing of the adhesive 4.

(Second Embodiment) FIGS. 3A to 4
FIG. 6C is a sectional view showing a manufacturing process of the semiconductor device according to the second embodiment. As shown in FIG. 4C, in the semiconductor device of this embodiment, two semiconductor chips are stacked and a wire is used for electrical connection between the semiconductor chip and the printed wiring board. In addition, FIG.
Before the steps shown in FIGS. 1A to 1C, the semiconductor chip 1 is temporarily adhered onto the printed wiring board 2 by the steps shown in FIGS. 1A to 1C (die bonding step).

First, in the steps shown in FIGS.
The second semiconductor chip 11 is temporarily adhered onto the semiconductor chip 1 with the second adhesive 14. Here, FIG.
As the bonding method shown in (c), there are shown in FIGS.
There are three methods as shown in, and the description is omitted here. Here, the second adhesive 14 is in a temporarily cured state, and the semiconductor chip 1 and the second semiconductor chip 11 are in a temporarily bonded state.

Next, in the step (wire bonding step) shown in FIG. 4A, the wire 3 is used to connect the semiconductor chip 1 to the internal connection land 2a in the printed wiring board 2. Then, using the wire 13, the second semiconductor chip 1
1 and the land 2a for internal connection are connected. If the connection order is reversed, the tool for feeding the wire 3 may come into contact with the wire 3 of the second semiconductor chip 11 during wire bonding of the semiconductor chip 1 and cause a defect. Further, it is preferable that the wire 3 and the wire 13 have different loop shapes so that the wire 3 and the wire 13 do not come into contact with each other.

Next, the step shown in FIG. 4B (sealing step)
Move on to. The semiconductor device assembled so far is held between the upper mold 20a and the lower mold 20b heated to 160 to 190 ° C., and the sealing resin 5 is transfer-injected. After the completion of the injection, the sealing resin 5 covering the semiconductor device is cured to a predetermined degree by performing heat treatment by holding at 160 to 190 ° C. for 30 seconds to 2 minutes. This curing is performed to such an extent that the sealing resin 5 is not sufficiently cured when the semiconductor device that has been sealed is taken out from the mold, so that the sealing resin 5 is not damaged. At this time, the adhesive 4 and the second adhesive 14 that were in the temporarily cured state
Also cures to a certain extent.

At the time of this heat treatment, 50 kgf / cm ² to 2 kg is used in order to crush the air mixed in at the time of injecting the resin.
A pressure of about 50 kgf / cm ² is applied to the sealing resin 5.
This pressure also acts as hydrostatic pressure that presses the semiconductor chip 1, the second semiconductor chip 11 and the printed wiring board 2 against the lower die 20b, so that the warpage of the semiconductor chip 1, the second semiconductor chip 11 and the printed wiring board 2 is prevented. It is corrected to a flat state. At the same time, the insufficient wetting region and voids inside the adhesive 4 and the second adhesive 14 are collapsed. In this state, the sealing resin 5,
Since the adhesive 4 and the second adhesive 14 are cured, it is possible to obtain a uniform and strong adhesive interface without insufficient wetting.

Next, in the step (after-cure step) shown in FIG.
The sealing resin 5, the adhesive 4, and the second adhesive 14 are completely cured by holding them at 0 to 190 ° C. for 3 to 8 hours for heat treatment. In order to completely cure the adhesive 4 and the second adhesive 14, it is generally preferable to perform heat treatment at 150 ° C. to 180 ° C. for 30 minutes to 1 hour. The adhesive 4 and the second adhesive 14 are also after-cured. It is completely cured in the process. Through the above steps, the manufacturing of the semiconductor device in this embodiment is completed.

In the present embodiment, the bonding strength between the semiconductor chip 1 and the printed wiring board 2 and the bonding strength between the stacked semiconductor chips can be increased as compared with the conventional manufacturing method, so that the reliability of the semiconductor device is improved. Can be improved. In the simplification of the manufacturing process, it is not necessary to perform the die bond curing process for each of the adhesive 4 and the second adhesive 14, and therefore, a larger effect can be obtained as compared with the first embodiment.

In this embodiment, the adhesive 4 and the second adhesive 14 are preferably of the same type in terms of work. However, they may be different species, depending on the quality required.

Further, in this embodiment, after the step of curing the adhesive 4 almost completely, the process shown in FIG.
In the step shown in (c), even if the second adhesive 14 and the sealing resin 5 are cured, the warp of the printed wiring board 2 can be corrected and the adhesion of the second adhesive 14 can be improved. it can.

Although omitted in the steps shown in FIGS. 3 (a) to 4 (c), it is possible to improve the wire bondability in the wire bonding step and the adhesion with the sealing resin. For the purpose, it is possible to insert the plasma cleaning step after die bonding or wire bonding, since it does not directly affect the curing of the adhesive.

(Third Embodiment) FIGS. 5A to 6
FIG. 7C is a sectional view showing a manufacturing process of the semiconductor device according to the third embodiment. As shown in FIG. 6C, in the semiconductor device of this embodiment, two semiconductor chips are stacked and bumps are used for electrical connection between the semiconductor chips. Before the steps shown in FIGS. 5A to 5C, the semiconductor chip 1 is placed on the printed wiring board 2 by the steps shown in FIGS. 1A to 1C (die bonding step). Temporarily bonded.

First, in the steps shown in FIGS.
The second semiconductor chip 11 is temporarily bonded onto the semiconductor chip 1 by the second adhesive 14 in a face-down manner. Here, one of the steps in FIGS. 1A to 1C is selected.

Bump 8 formed on one semiconductor chip
The order of connecting to the other semiconductor chip includes a method of performing before the placement of the second adhesive 14 and a method of performing after. The semiconductor chip forming the bump 8 may be the semiconductor chip 1, the second semiconductor chip 11, or both the semiconductor chip 1 and the second semiconductor chip 11. Here, a method of forming the bump 8 on one semiconductor chip in advance and connecting it to another semiconductor chip after the mounting of the second adhesive 14 is described as an example. The method of can also be applied.

In the step shown in FIG. 5A, after the paste type second adhesive 14 is applied on the semiconductor chip 1 at room temperature, the second semiconductor chip 11 is preliminarily prepared.
The second semiconductor chip 11 is mounted so that the bumps 8 formed in (1) face downward (face-down method). At this time, the mounting position of the second semiconductor chip 12 is aligned so that the bump positions match with the predetermined first semiconductor chip. After that, in-line curing is performed at 100 to 250 ° C. for several tens of seconds to several minutes to temporarily cure the second adhesive 14.

In the step shown in FIG. 5B, after the paste type second adhesive 14 is applied on the semiconductor chip 1 at room temperature, the second semiconductor chip 11 is faced down (face down method). To be installed on. Here, the bumps 8 are formed in advance on the semiconductor chip 1, and the positions of the second semiconductor chips 11 are aligned so that the second semiconductor chips 11 are aligned with the positions of the bumps of the semiconductor chips 1. After that, in-line curing is performed at 100 to 250 ° C. for several tens of seconds to several minutes to temporarily cure the second adhesive 14.

In the step shown in FIG. 5C, the film type second adhesive 14 is applied on the semiconductor chip 1 by 5
Hold at 0 to 150 ° C. for several seconds and perform thermocompression bonding. in addition,
Second semiconductor chip 11 facing down (face-down method)
And then thermocompression bonded by holding at 100 to 200 ° C. for several seconds. At this time, the bumps 8 are formed in advance on the second semiconductor chip 11, and the mounting position of the second semiconductor chip 11 is aligned so that the bumps 8 and the semiconductor chip 1 are aligned with each other. Then, when thermocompression bonding is performed, the second pressure is set so that the bumps 8 penetrate the second adhesive 14 and complete contact with the semiconductor chip 1 is made.
In addition to the semiconductor chip 11, the second adhesive 14 is temporarily hardened.

Here, as the method of forming the bumps 8, there are a printing method, a mask vapor deposition method, a wire bonding method, a plating method, a transfer method and the like. The material of the bump 8 is Ag,
There are Au, Cu, solder and the like. Further, as the second adhesive 14, in addition to a paste or film made of an epoxy resin, an anisotropic conductive paste or an anisotropic conductive film in which conductive particles are dispersed in an epoxy resin can be used. .

Next, in the step (wire bonding step) shown in FIG. 6A, the semiconductor chip 1 and the internal connection lands 2a of the printed wiring board 2 are electrically connected by the wires 3.

Next, the step (sealing step) shown in FIG. 6B.
Then, the semiconductor device assembled up to now (after wire bonding) is held between the upper mold 20a and the lower mold 20b heated to 160 to 190 ° C., and the sealing resin 5 is transferred to the predetermined space. inject. 160 ~ 19 after injection
The encapsulating resin 5 is cured to a predetermined degree by performing a heat treatment by holding it at 0 ° C. for 30 seconds to 2 minutes. This curing is performed when taking out the sealed semiconductor device from the mold.
The sealing resin 5 is cured to such an extent that it is not damaged due to insufficient curing. At this time, the adhesive 4 and the second adhesive 14 that were in the temporarily cured state are also cured to a predetermined degree.

At the time of this heat treatment, 50 kgf / cm ² to 2 kg was used in order to crush the air mixed during the injection of the resin.
A pressure of about 50 kgf / cm ² is applied to the sealing resin 5.
This pressure also acts as hydrostatic pressure that presses the semiconductor chip 1, the second semiconductor chip 11 and the printed wiring board 2 against the lower die 20b, so that the warpage of the semiconductor chip 1, the second semiconductor chip 11 and the printed wiring board 2 does not occur. It is corrected to a flat state. At the same time, the insufficient wetting region generated at the interface between the adhesive 4 and the second adhesive 14 and the voids generated inside are crushed. In this state, the sealing resin 5, the adhesive 4 and the second adhesive 14 are cured, so that a uniform and strong adhesive interface without an insufficient wetting region can be obtained.

Next, in the step (after-cure step) shown in FIG. 6C, the semiconductor device after the sealing step is put into an oven 9 and held at 160 to 190 ° C. for 3 to 8 hours for heat treatment. Thus, the sealing resin 5, the adhesive 4 and the second adhesive 14 are completely cured. Through the above steps, the manufacture of the semiconductor device of this embodiment is completed.

In this embodiment, the adhesive strength between the semiconductor chip 1 and the printed wiring board 2 and the adhesive strength between the semiconductor chip 1 and the second semiconductor chip 11 can be increased as compared with the conventional manufacturing method. The reliability of the semiconductor device can be improved. It is also possible to simplify the process.

Further, in the present embodiment, the sealing resin 5 and the second adhesive 14 are hardened in a state where the second semiconductor chip 11 is pressed against the semiconductor chip 1 with the bumps 8 interposed therebetween, so that the bumps 8 are joined together. It becomes stronger and the reliability of electrical connection can be improved.

Generally, if bumps are included in the region bonded by the adhesive, the adhesiveness between the base and the semiconductor chip is deteriorated due to insufficient wetting of the adhesive, and the electrical connection of the semiconductor chip is directly caused. make worse. Therefore, it is extremely effective to apply the present invention to improve the adhesion.

In the present embodiment, the adhesive 4 and the second adhesive 14 are preferably of the same type in terms of work. However, they may be different species, depending on the quality required.

In addition, in this embodiment, after the step of curing the adhesive 4 almost completely, the process shown in FIG.
In the step shown in (c), even if the second adhesive 14 and the sealing resin 5 are cured, the warp of the printed wiring board 2 can be corrected and the adhesive strength of the second adhesive 14 can be increased. it can.

Although omitted in the steps shown in FIGS. 5A to 6C, it is possible to improve the wire bondability in the wire bonding step and the adhesion with the sealing resin. For the purpose, it is possible to insert the plasma cleaning step after die bonding or wire bonding, since it does not directly affect the curing of the adhesive.

(Other Embodiments) The present invention is shown in FIG.
It can also be applied to the structure shown in FIG. In the structure shown in FIG. 8A, the printed wiring board 102 is
Two semiconductor chips are stacked on top of each other, and bumps 108 are used for electrical connection between the printed wiring board 102 and the semiconductor chip 101.

In this case, as a step of completely curing the adhesive 104 for adhering the printed wiring board 102 and the semiconductor chip 101 and the second adhesive 114 for adhering the semiconductor chip 101 and the second semiconductor chip 111, Third
The sealing process and the after-curing process described in the above embodiment may be used. Then, the warp of the printed wiring board 101 is corrected to correct the semiconductor chip 101 and the printed wiring board 102.
The adhesive strength between the semiconductor chip 101 and the second semiconductor chip 111 can be improved, and the process can be simplified.

The present invention is also applied to the case where the semiconductor chip 101 is mounted on the printed wiring board 102 in a face-down manner in the structure as shown in FIG. 7A, and the bumps are used for electrical connection between the both. be able to.

The present invention can also be applied to the structure shown in FIG. 7 (c). Further, in the structure shown in FIG. 7C, the semiconductor chip 101 is connected to the printed wiring board 102.
It can also be applied to the case where the components are mounted in a face-down manner and the bumps are used for electrical connection between the both.

Although the printed wiring board shown in the above embodiment does not show a solder resist for protecting the conductor, the effect of the present invention is exerted regardless of the presence or absence of the solder resist. It is also possible to apply to a printed wiring board provided with.

Further, in the above embodiment, the case where the base is the rigid organic printed wiring board 2 is described, but in the present invention, the same effect can be obtained even if a ceramic substrate or a flexible wiring board is used as the base. Can be obtained.

[0108]

According to the method of manufacturing a semiconductor device of the present invention, the curing of the adhesive is performed simultaneously with the curing of the sealing resin under the application of pressure to the sealing resin in the sealing step. As a result, the resin sealing pressure acts as a hydrostatic pressure that presses the semiconductor chip and the support, so that the warp of the support is corrected to reduce the insufficient wetting area at the adhesive interface, and to suppress voids inside the adhesive. Is possible. Therefore, since it is possible to improve the adhesion between the support and the semiconductor chip,
A highly reliable semiconductor device can be obtained. Moreover, the process can be simplified.

[Brief description of drawings]

1A to 1C are cross-sectional views showing a manufacturing process of a semiconductor device according to a first embodiment.

2A to 2C are cross-sectional views showing a manufacturing process of the semiconductor device according to the first embodiment.

3A to 3C are cross-sectional views showing a manufacturing process of the semiconductor device according to the second embodiment.

4A to 4C are cross-sectional views showing the manufacturing process of the semiconductor device according to the second embodiment.

5A to 5C are cross-sectional views showing a manufacturing process of a semiconductor device according to a third embodiment.

6A to 6C are cross-sectional views showing the manufacturing process of the semiconductor device according to the third embodiment.

7A to 7C are cross-sectional views showing a typical internal structure of a conventional BGA semiconductor device.

8A and 8B are cross-sectional views showing a typical internal structure of a conventional BGA semiconductor device.

9A to 9D are cross-sectional views showing a process of manufacturing a semiconductor device having the structure shown in FIG. 7A.

10A to 10C are cross-sectional views showing a process of manufacturing a semiconductor device having the structure shown in FIG. 7A.

11A to 11D are cross-sectional views showing a process of manufacturing a semiconductor device having the structure shown in FIG. 7B.

12A to 12C are cross-sectional views showing a process of manufacturing a semiconductor device having the structure shown in FIG. 7B.

13A and 13B are cross-sectional views showing the steps of manufacturing a semiconductor device having the structure shown in FIG. 7B.

14A and 14B are cross-sectional views showing a process of manufacturing a semiconductor device having the structure shown in FIG. 7B.

15A and 15B are cross-sectional views for explaining a defect in a conventional method for manufacturing a semiconductor device.

16 (a) and 16 (b) are cross-sectional views for explaining a defect in the conventional method for manufacturing a semiconductor device.

[Explanation of symbols]

1 semiconductor chip 2 printed wiring board 2a Land for internal connection 2b wiring pattern 2c via hole 2d Land for external terminal 2e Insulation member 3 wires 4 adhesive 5 Sealing resin 6 metal balls 8 bumps 9 oven 11 Second semiconductor chip 13 wires 14 Second adhesive 20a upper mold 20b Lower mold

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Claims (9)

[Claims] 1. A method of manufacturing a semiconductor device, wherein a semiconductor chip, a support on which the semiconductor chip is mounted, and an adhesive for adhering the semiconductor chip and the support are sealed with a sealing resin. Then, in the step of sealing the support, the semiconductor chip, and the adhesive with the sealing resin in a sealing mold, pressure is applied to the sealing resin to cure the adhesive. A method for manufacturing a semiconductor device, comprising the step (a) of performing at least a part of the above and at least a part of curing of the sealing resin. 2. The method of manufacturing a semiconductor device according to claim 1, wherein the semiconductor chip is mounted on the support in a face-down manner, and the semiconductor chip and the support are electrically connected by bumps. A method for manufacturing a semiconductor device, comprising: 3. The method of manufacturing a semiconductor device according to claim 1, wherein a second semiconductor chip is mounted on the semiconductor chip with a second adhesive interposed therebetween, and in the step (a), the second semiconductor chip is mounted. A method of manufacturing a semiconductor device, characterized in that at least a part of curing of the second adhesive is also performed. 4. The method of manufacturing a semiconductor device according to claim 3, wherein the second semiconductor chip is mounted on the semiconductor chip by a face-down method, and the second semiconductor chip and the semiconductor chip are electrically connected. A method for manufacturing a semiconductor device, which is performed by bumps. 5. The method of manufacturing a semiconductor device according to claim 1, wherein the semiconductor chip is plural, and in the step (a), the semiconductor chip and the support are bonded to each other. A method for manufacturing a semiconductor device, characterized in that at least a part of the curing of the adhesive is performed. 6. The method for manufacturing a semiconductor device according to claim 1, wherein in the step (a), the curing of the adhesive and the sealing resin is completed. Manufacturing method. 7. A semiconductor chip, a second semiconductor chip mounted on the semiconductor chip, and a second adhesive for bonding the semiconductor chip and the second semiconductor chip together are sealed with a sealing resin. A method of manufacturing a semiconductor device, wherein the semiconductor chip, the second semiconductor chip, and the second adhesive are sealed with the sealing resin in a sealing mold,
A method of manufacturing a semiconductor device comprising a step (a) of applying a pressure to the sealing resin to perform at least a part of the curing of the second adhesive and at least a part of the curing of the sealing resin. 8. The method of manufacturing a semiconductor device according to claim 7, wherein the second semiconductor chip is mounted on the semiconductor chip by a face-down method, and the second semiconductor chip and the semiconductor chip are electrically connected to each other. A method for manufacturing a semiconductor device, which is performed by bumps. 9. The method of manufacturing a semiconductor device according to claim 7, wherein in the step (a), curing of the second adhesive and the sealing resin is completed. Production method.